Substrate specificities of porcine and bovine enteropeptidases toward the peptide Val-(Asp)4-Lys-Ile-Val-Gly and its analogs.

The substrate specificities of porcine and bovine enteropeptidases were investigated using the peptide Val-(Asp)(4)-Lys-Ile-Val-Gly and its various analogs with mutations in the (Asp)(4)-Lys sequence as substrates. The results indicated that in addition to P1 Lys, P2 Asp in the substrates is most important, that P3 Asp is additionally important, and that P5 Asp contributes somewhat to the susceptibility, and that P4 Asp is the least important. These results were essentially identical as between porcine and bovine enteropeptidases.